The present invention generally relates to air conditioning apparatus and, in a representatively illustrated embodiment thereof, more particularly relates to condensate drain pan structures used in conjunction with air conditioning cooling coils.
A coil used in air conditioning apparatus such as furnaces, air handling units, heat pumps and packaged air conditioners extracts moisture from the air which is being flowed externally across the coil (by a blower portion of the apparatus and cooled by the coil for delivery to a conditioned space served by the apparatus. This moisture extraction creates condensation (water) on the exterior of the coil which drips from the coil into an associated drain pan structure within the outer housing of the air conditioning apparatus. Coil condensation dripping into the pan flows away therefrom by gravity via a condensate drain line suitably connected to the pan.
Packaged self-contained heat pumps and air conditioners are typically positioned outside of a building (such as on the roof or on the ground adjacent the building) which they serve. In several conventional designs of such a packaged unit its condensate drain pan underlies the portion of the cooling coil which is interposed in the return air/supply air conditioned air stream and catches and drains away condensate falling from this coil portion. However, in these conventional air conditioning apparatus designs, coil tubing return bends which are not disposed in the cool conditioned air stream project outwardly from an end of the coil and beyond the condensate-receiving periphery of the underlying drain pan.
Because packaged units of this type are normally positioned outdoors, it was not thought necessary to use a drain pan structure to catch and drain away this relatively minor condensate drippage from these exposed coil tubing return bends. However, in time, this minor condensate drippage tended to leak out of the housing of the packaged unit and, when observed by the owner of the unit, triggered “nuisance” service calls to fix what, in reality, was neither a defect in or a problem with the unit.
In view of this it would be desirable to provide a modified drain pan which additionally receives and drains away this coil tubing return bend condensate without having to modify the unit in which the drain pan is installed. It is to this goal that the present invention is directed.